(define x '(1 2 3))
(define k-if #f)

(display "原始x的值: ")
(display x)
(display "\n")

(display "执行if表达式...\n")
(define initial-result
  (if (call/cc
          (lambda(k)
              (set! k-if k)
              (null? x)))
      '()
      (cdr x)))

(display "初始结果: ")
(display initial-result)
(display "\n\n")

(display "调用(k-if #t)...\n")
(define result-t (k-if #t))
(display "result-t的值: ")
(display result-t)
(display "\n\n")

(display "调用(k-if #f)...\n")
(define result-f (k-if #f))
(display "result-f的值: ")
(display result-f)
(display "\n")